Study on On-Line Monitoring Method for Grinding Quality

Abstract: The goal of system monitoring and diagnostics is to minimize economic losses, to increase stability, to maximize productivity, and to maintain product quality in manufacturing. The feature extraction from the signals acquired in rotating machine is required for performance evaluation, condition monitoring, and fault diagnostics. In this paper, we extracted the distinctive features from vibration signals gathered in rotor-bearing system during acceleration in order to monitor an abnormal condition by using various kinds of signal processing methods such as the Fast Fourier Transform, Short-Time Fourier Transform, Wigner-Ville Distribution, and Discrete Wavelet Transform.

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Error Compensation Method of Harmonic Analysis for Time Grating Sensor

Authors: Zi Ran Chen, Dong Lin Peng, Yong Zheng, Fang Yan Zheng, Tian Heng Zhang

Abstract: Due to the complexity of measurement system, it is hard correct errors by using traditional error separation and error tracing technology. To reduce the production cost and improve the measurement accuracy, a novel error compensation method based on harmonic analysis is presented in this paper. In this way, high precision time grating sensors can be manufactured with low precision mechanical machining method. The experiment results prove that errors can be reduce within ±2″.

3850

Study on Porcelain Acoustic Emission Signal Based on All Phase Spectrum Analysis

Authors: Ding Ye, Wei Jin, Chen Xi Liu

Abstract: In order to differentiate the porcelain quality, the paper introduces the All Phase spectrum analysis technology and studies on analyzing porcelain acoustic emission (AE) signal. As for the energy leakage by traditional signal truncation method in processing the signal, the all phase truncation method somewhat reduce the leakage which affects the follow-up porcelain quality discrimination. All instances consisting sample point are considered and weighted average technology is introduced to make amplitude-frequency clearer. According to the simulation, the energy leakage based on all phase signal processing is weakened and the spectrum is able to be accurate. It is more beneficial to the follow-up porcelain quality discrimination.

569

Identification of Damage Modes in Twill-Weave Composite Based on EMD of AE Event

Authors: Wen Qin Han, Jin Yu Zhou

Abstract: Acoustic emission (AE) monitoring is the primary technology used for the identification of different types of failure in composite materials. Tensile test were carried out on twill-weave composite specimens, and acoustic emissions were recorded from these tests. AE signals were decomposed into a set of Intrinsic Mode Functions(IMF) components by means of Empirical Mode Decomposition(EMD) , the Fast Fourier Transform (FFT) of each IMF component was performed, it was shown that the event peak frequency of each IMF component could be directly related to the materials damage modes.

An Automatic Measurement for Pipeline Thickness Detection Using Ultrasonic Method

Authors: Bo Dai, Ming Lu Ma

Abstract: The measurement of wall thickness of pipelines is an important procedure of pipeline corrosion inspection. This procedure can be done automatically in a computer by processing data acquired from ultrasound probe, forming C-scan image, and running thickness detection algorithms. This paper presents in detail the comparison of three ways of processing, which are FFT algorithm, twice FFT algorithm, and improved twice FFT algorithm. The final results show that improved twice FFT algorithm has the best precision compared with the other two algorithms. It has higher accuracy than FFT algorithm and less decision error than twice FFT algorithm. Using this method, defects of a pipeline can be identified and measured effectively using ultrasonic wave.

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